Analyses of Ground-based and Satellite Observations for Developing a Dust Climatology in Central and East Asia

In support of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), we have been working on the development of the Asian Dust Databank by integrating the diverse satellite and ground-based data on mineral dust, land-cover and land-use change (LCLUC), and climatic variables in Central and East Asia. The ultimate goal of this effort is to gain a better understanding of interactions between LCLUC, atmospheric dust, and their linkages to climate changes which have been observed in Northern Eurasia over the past 50 years. This study will present an in-depth analysis of 50-year ground-based observations of visibility and WMO present weather from selected meteorological stations in Central and East Asia. We examine the duration, intensity, frequency and area coverage of dust events on a case-by-case basis, addressing the regional importance of natural and human-disturbed dust sources. We also present a new methodology for developing a reliable dust climatology by merging visibility and WMO dust present weather records. Visibility data can potentially provide quantitative information on dust events. However, the visibility reduction is caused not only by dust but also by other factors (e.g., haze, smoke, fog, mist, rain, snow). The advantage of WMO dust present weather is that it serves as a direct indicator of atmospheric dust, although in the qualitative way. Our analysis reveals various inconsistencies between visibility and dust present weather records that question the accuracy of dust frequency reported by previous studies based on visibility records only. In addition, we will present examples of integrated analyses of ground-based data and satellite observations (e.g., TOMS AI, MODIS aerosol products and true color images) with the goal of developing a new observation-based climatology of dust events.